<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

    <button>点击</button>

    <script>
        // 练习: 单击时触发单击事件， 双击时只触发双击事件
        // BOM: setTimeOut()

        var time = null;


        var btn = document.querySelector('button');
        btn.addEventListener('click', fn);
        btn.addEventListener('dblclick', fn1);
        function fn() {
            clearTimeout(time);
            time = setTimeout(() => {
                alert('2班')
                console.log(time);
            }, 200);

            // btn.removeEventListener('click',fn);
        }
        function fn1() {
            console.log(time);
            clearTimeout(time);
            alert('4班');
        }

    </script>
</body>

</html>